//1. Number
var a = 10;
//2. String 类型
var str = 'abc';
//3. Boolean
var isDone = true;
// 4.Array
var arr = [{ a: 1 }, { a: 2 }];
var arr2 = ['a', 'b'];
// let arr = ['123', 12, true];
// const sym = Symbol();
// let obj = {
//   [sym]: 'semlinker'
// };
// console.log(obj[sym]);
console.log(arr2);
function greet(person) {
}
//枚举 : 星期 一 日 C# java
//enum  关键字 : 声明一个枚举类型的数据
var Week;
(function (Week) {
    Week[Week["ONE"] = 0] = "ONE";
    Week[Week["TWO"] = 1] = "TWO";
    Week[Week["THREE"] = 2] = "THREE";
    Week[Week["FOUR"] = 3] = "FOUR";
    Week[Week["FIVE"] = 4] = "FIVE";
    Week[Week["SIX"] = 5] = "SIX";
    Week[Week["SEVEEN"] = 6] = "SEVEEN";
})(Week || (Week = {}));
console.log(Week.ONE);
console.log(Week.TWO);
console.log(Week.THREE);
// 对象
Object.keys(Week).map(function (item) { return console.log(item); });
// any ts就失去了意义
var abc = 123;
var abc2 = '123';
//unknown : 不知道
var value;
value = '123';
value = 123;
value = true;
var value2 = value;
// unknow 类型只能被赋值给any和unknow本身
// let value3: boolean = value;// 报错
var nul;
var und;
nul = null;
und = undefined;
